> All a blockchain is, is a Merkle tree with a third party that ensures there is only one “main line”.
No. The "wasteful part" is also part of the definition of the blockchain.
Just because the word "blockchain" seems to describe only the data structure, doesn't mean that's the case.
The innovation was to couple a Merkle tree with a proof-of-work system. Both existed before in standalone forms. The Merkle tree in many, many applications, the proof-of-work for example in Hashcash to combat email spam.
Only the combination of both reached a level of novelty that deserved a new name.
(That we still haven't found a single compelling use case is another matter.)
What you mean is indeed succinctly and correctly named "Merkle tree" or "hash tree". It would have been wasteful to coin another word for it.
Blockchains are just a datastructure and proof of work is not a strict requirement. I believe the rising popularity of Proof of Stake blockchains will make that evident.
> proof of work is not a strict requirement. I believe the rising popularity of Proof of Stake blockchains will make that evident.
I thought for a second whether I should include PoS and other schemes, but decided (wrongly) that nobody would try to squeeze imaginary internet points out of being willfully misunderstanding.
But so be it: proof of stake is a different mechanism that fulfills the same role as proof of work in blockchains.
My comment had nothing to do with imaginary internet points. You just said being wasteful was part of the definition of a blockchain which is a common argument people like to make when promoting the false idea that blockchains are inherently bad for the environment. It felt important to point out that there are non-wasteful ways of accomplishing the same thing as PoW.
There is no requirement that blockchains must be secured by proof of work. Many blockchains use proof of stake. A blockchain is one or more Merkle Trees plus an external ledger saying what the last state of each tree is. The innovative piece is Consensus about this last thing. How it is achieved can vary. Ultimately consensus is achieved by the end users checking the results.
No. The "wasteful part" is also part of the definition of the blockchain.
Just because the word "blockchain" seems to describe only the data structure, doesn't mean that's the case.
The innovation was to couple a Merkle tree with a proof-of-work system. Both existed before in standalone forms. The Merkle tree in many, many applications, the proof-of-work for example in Hashcash to combat email spam.
Only the combination of both reached a level of novelty that deserved a new name.
(That we still haven't found a single compelling use case is another matter.)
What you mean is indeed succinctly and correctly named "Merkle tree" or "hash tree". It would have been wasteful to coin another word for it.